Process of making intraground waterproof baffles and a device therefor

ABSTRACT

Method of and apparatus for the formation of fluid-impermeable underground walls wherein a trench excavator carrying a roll of flexible waterproof foil is displaced along an excavation line so that, as the trench is cut, the foil is laid in a vertical plane behind the excavator, and the space between the foil and the flanks of the cut is filled.

United States Patent 7 (ll/3 l 61/35, 61/63, 61172.6, 47/39 i l l I I I [51] Int. Cl E021 5/522 [50] Field of Search 61/72.],

[56] References Cited UNITED STATES PATENTS 3,309,875 3/1967 Niederwemmer 6l/72.6 X 2,636,288 4/1953 Thomas 37/86 3,298,183 1/1967 Grether eta] 61/72.] 3,327,484 6/1967 Launder et al 61/726 Primary Examiner-Jacob Shapiro Attorney-Karl F. Ross ABSTRACT: Method of and apparatus for the formation of fluid-impermeable underground walls wherein a trench excavator carrying a roll of flexible waterproof foil is displaced along an excavation line so that, as the trench is cut, the foil is laid in a vertical plane behind the excavator, and the space between the foil and the flanks of the cut is filled.

I I. r

PROCESS OF MAKING INTRAGROUND WATERPROOF BAFFLES AND A DEVICE THEREFOR The invention comprises a process and a device therefor, for making intraground waterproof baffles or barriers, provided with one or more strips of thin, flexible insulating material inserted therein as are widely used in hydraulic engineering in order to prevent infiltration of water into protected areas.

According to prior art techniques such intraground waterproof baffles with inserted strips of thin insulating material, which prevent infiltration of water into the protected areas, are made of one or more layers of an insulating material introduced as a curtain into a cut previously excavated in the subsurface. The introduction of the insulating material is carried out apart from the device for excavating the cut.

The materials mostly used for this purpose are: asphalt-impregnated jute; vinyl, rubber or plastic, e.g. polyethylene, foil; thins asphalt-impregnated fiberboard; paper; waterproof cloth and the like.

According to known techniques the insulating materials are introduced into the cut in form of vertical sections, being dropped into place in the form of a curtain. The sections are provided with kentledges or ballast weights.

The device for performing this operation has a horizontally positioned drum with a thin, insulating material reeled thereon. The drum is mounted on a separate support, located above the cut and shifted independently from the excavating device. The kentledges attached to the edge of each segment enable unreeling of a thin insulating material and inserting it into the excavated cut.

The disadvantage of the technique mentioned above lies in the considerable frictional resistance encountered in the course of inserting the insulating material into the out which is filled with a dense suspension in order to support the walls of the cut.

Moreover, the horizontal positioning of kentledges is very difficult due to irregularities of the bottom of said cut, and also the accurate joining of the edges of two adjacent sections is not practicable; hence, gaps occur in those places where the adjacent sections overlap one another.

These shortcomings necessitate hoisting out the inserted sections of an insulating material, cleaning and trimming the bottom of the cut and reinserting the section of insulating material therein. These are very laborious and time-consuming operations. A further disadvantage of vertical insertion of a thin insulating material into'intraground cuts is loss of this material in overlaps.

Hence, the present invention has as its object to save operating costs and to simplify the process of making intraground waterproof baffles. Another object is to reduce the time consumed in producing such baffles and to improve their scaling properties.

These problems are solved according to the invention by inserting a drum with a thin, flexible insulating material reeled thereon into the cut excavated under the protection of a water-clay suspension with the axle of this drum in vertical position.

The process according to the invention comprises introducing a thin, flexible insulating material into the cut simultaneously with shifting the excavating machine, whereas the space between vertical walls of the cut and an insulating material is filled with a suitable material in known manner.

The invention will become more readily apparent from the accompanying drawing in which:

FIG. 1 is a vertical section; and

FIG. 2 is a horizontal section through the apparatus.

The device, according to the invention, comprises a cutter bar 2 provided at its bottom part with a hinged connector 3, a sheet guard 4 mounted therein, and with apron flashings 5 protecting against penetration of a suspension within the guard 4 and against infiltration of a filling material from trench section 6 to section 7.

The drum 8 carrying a thrn flexible insulating material 9 reeled thereon is mounted within the guard.

An insulating material is fastened at one edge to a tubular post 10 being fixed in the bottom of the cut especially for this purpose and counterbalanced at its upper lid by means of tension members and anchors 11. The downward pressure of the cutter bar is controlled by means of a hydraulic mechanism or screw gear 13 and the cutter chain is driven by the driving motor 14. The drum shaft is mounted in movable bearings 12. The shift direction of the device is marked by number 15.

A thin flexible insulating material unreels along the cut progressively in the course of shifting the excavating machine which creates the trench 6, 7.

After unreeling of the insulating material and filling of the space'between the material and walls of the cut, the tubular post is drawn out from the bottom of the cut.

I claim:

1. An apparatus for producing fluid-impermeable underground barriers, comprising a bucket-type trench-excavating head displaceable along an excavation line to cut a trench in the ground; means for displacing said head along said line; support means for a roll of flexible waterproof foils coupled with said head and having an upright axis for paying out said foil in an upright sheet progressively with displacement of said head whereby said foil is positioned in the trench cut by said head between the walls thereof, and subsequent filling of the gap between said foil and said wall supports said foil, said head being provided with a hinged connection extending rearwardly of the direction of displacement of said head along said line and carrying said support; and a sheet guard ahead of said roll and a pair of aprons extending rearwardly from said sheet guard toward said walls of said trenchfor sealing the portion of the trench ahead of said roll from the portion of the trench behind said roll, said foil being laid in said portion of said trench behind said foil.

2. A method of forming a fluid-impenetrable subsurface barrier comprising the steps of: continuously excavating a trench along an excavation line in the presence of a solid-inliquid suspension; progressively with the excavation of said trench, displacing a roll of a flexible waterproof foil along said trench with said roll positioned for rotation about an upright axis while laying said foil in said trench in an upright state; progressively shielding said roll in said foil from said suspension as said roll is advanced along said trench; and filling the space between said foil and the wall of said trench. 

1. An apparatus for producing fluid-impermeable underground barriers, comprising a bucket-type trench-excavating head displaceable along an excavation line to cut a trench in the ground; means for displacing said head along said line; support means for a roll of flexible waterproof foils coupled with said head and having an upright axis for paying out said foil in an upright sheet progressively with displacement of said head whereby said foil is positioned in the trench cut by said head between the walls thereof, and subsequent filling of the gap between said foil and said wall supports said foil, said head being provided with a hinged connection extending rearwardly of the direction of displacement of said head along said line and carrying said support; and a sheet guard ahead of said roll and a pair of aprons extending rearwardly from said sheet guard toward said walls of said trench for sealing the portion of the trench ahead of said roll from the portion of the trench behind said roll, said foil being laid in said portion of said trench behind said foil.
 2. A method of forming a fluid-impenetrable subsurface barrier comprising the steps of: continuously excavating a trench along an excavation line in the presence of a solid-in-liquid suspension; progressively with the excavation of said trench, displacing a roll of a flexible waterproof foil along said trench with said roll positioned for rotation about an upright axis while laying said foil in said trench in an upright state; progressively shielding said roll in said foil from said suspension as said roll is advanced along said trench; and filling the space between said foil and the wall of said trench. 